save cookie and filesystem sessions and allow custom session backends

 This package provides a Go library that implements methods to save
 cookies and filesystem sessions and allows custom session backends.
 It is provided by Gorilla which is a web toolkit for the Go
 programming language.
 .
 Features:
   - Simple API: use it as an easy way to set signed cookies
   - Cookies can optionally be enycrpted
   - Built-in backends to store sessions in cookies on the filesystem
   - Flash messages: session values that last until read
   - Session persistency switching
   - Methods to rotate authentication and encryption keys
   - Multiple sessions per request, even using different backends
   - Support for custom session backends